1. Field of the Invention
The invention relates to a display apparatus for an active matrix type and a method for driving a display apparatus.
2. Description of the Related Art
In an active matrix type liquid crystal display (LCD) apparatus, a plurality of scanning lines is arranged in rows of a display, and a plurality of signal lines is arranged in columns. Each pixel is located among two scanning lines and two signal lines, and an image is displayed by applying desired voltages to the pixels. In conventional display apparatus, one signal line is required for each column of the pixels, and one scanning line is required for each row of the pixels. Therefore, the number of output terminals of source drivers for driving the signal lines (the number of terminals for connecting to the signal lines) is required to be the same as the number of the signal lines. Similarly, the number of output terminals of gate drivers for driving the scanning lines (the number of terminals for connecting to the scanning lines) is also required to be the same as the number of the scanning lines.
As a scheme for reducing the total number of output terminals (the number of connecting terminals), for example, a method is disclosed in Japanese Patent Application Laid Open JP2006-201315. In Japanese Patent Application Laid Open JP2006-201315, two TFTs are disposed across one signal line, and one of the TFTs is connected to a first scanning line and the other one of the TFTs is connected to a second scanning line. That technique also utilizes an image output circuit for applying image signals for four pixels, and has a first switching element and a second switching element for switching the image signals that are applied to a signal line. The first switching element and the second switching element can be alternately turned on by control signals from a first control line and a second control line, respectively. Thus, two pixels can be controlled by one signal line using two TFTs. As a result, the number of scanning lines is increased twice as much, and the number of signal lines is reduced to half. Therefore, when the number of rows is small and the number of columns is large, this technique can decrease the total number of output terminals.
However, in the method disclosed in Japanese Patent Application Laid Open JP2006-201315, although the number of signal lines may be reduced to half with respect to the number of pixels in each row as described above, the number of scanning lines is increased two-fold with respect to the number of pixels in each column. Thus, the total number of output terminals (the number of connecting terminals) cannot always be decreased.